As the synthesizing methods for said 3-substituted-3-oxo-2-(2,4-oxazolidinedione-3-yl)propionic acid amide compound, the following methods are conventionally proposed:
(1) a synthesizing method for obtaining said 3-substituted-3-oxo-2-(2,4-oxazolidinedione-3-yl)propionic acid amide compound by reacting 3-substituted-3-oxo-2-chloropropionic acid amides with potassium salts of 2,4-oxazolidinediones in acetonitrile (described in Japanese Patent Publication Open to Public Inspection (hereinafter referred to as JP-A) No. 48-66835); PA0 (2) a synthesizing method for obtaining said 3-substituted-3-oxo-2-(2,4-oxazolidinedione-3-yl)propionic acid amide compound by reacting the 3-substituted-3-oxo-2-chloropropionic acid amides with the 2,4-oxazolidinediones in the presence of potassium hydroxide (described in JP-A No. 52-115219); PA0 (3) a synthesizing method for obtaining said 3-substituted-3-oxo-2-(2,4-oxazolidinedione-3-yl)propionic acid amide compound by reacting the 3-substituted-3-oxo-2-chloropropionic acid amides with the 2,4-oxazolidinediones in the presence of potassium carbonate (described in JP-A No. 4-124661).
In these conventional synthesizing methods for said 3-substituted-3-oxo-2-(2,4-oxazolidinedione-3-yl)propionic acid amide compound, either a reaction by the use of salts of the 2,4-oxazolidinediones or a reaction in the presence of inorganic base is employed. In the former case, since it is necessary that the salts of the 2,4-oxazolidinediones are previously prepared or isolated, consequently the synthesizing is rather complex.
On the other hand, in the latter case, the reaction in the presence of the inorganic base has an adverse effect such that said reaction is accompanied by unpreferable side reactions, specifically in the later synthesizing processes, and consequently the reaction yield is lowered.